简介

Spring Cloud Gateway是Spring Cloud官方推出的第二代网关框架，取代Zuul网关。网关作为流量的，在微服务系统中有着非常作用，网关常见的功能有路由转发、权限校验、限流控制等作用

Git地址

https://gitee.com/wqrzsy/lp-demo/tree/master/lp-springboot-gateway

更多demo请关注

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基础项目

springboot spring cloud gateway demo实战项目

聚合

1. swagger

效果图：

image.png

聚合后通过访问gateway的swagger-ui页面就能访问所有微服务的swagger了，是不是很方便

先分享作者连接： https://blog.csdn.net/ttzommed/article/details/81103609

思路：通过gateway获取注册到eureka上的服务列表，然后把服务的url封装成swagger资源，让swagger-ui页面能获取到

关键类： swagger资源提供者

@Component
@Primary
public class SwaggerProvider implements SwaggerResourcesProvider {

    public static final String API_URI = "/v2/api-docs";

    public static final String EUREKA_SUB_PRIX = "CompositeDiscoveryClient_";

    private final DiscoveryClientRouteDefinitionLocator routeLocator;

    public SwaggerProvider(DiscoveryClientRouteDefinitionLocator routeLocator) {
        this.routeLocator = routeLocator;
    }

    @Override

    public List<SwaggerResource> get() {
        List<SwaggerResource> resources = new ArrayList<>();
        List<String> routes = new ArrayList<>();
        //从DiscoveryClientRouteDefinitionLocator 中取出routes，构造成swaggerResource
        routeLocator.getRouteDefinitions().subscribe(routeDefinition -> {
            String resourceName = routeDefinition.getId().substring(EUREKA_SUB_PRIX.length());
            String location = routeDefinition.getPredicates().get(0).getArgs().get("pattern").replace("/**", API_URI);
            resources.add(swaggerResource(resourceName, location));
        });
        return resources;
    }

    private SwaggerResource swaggerResource(String name, String location) {
        SwaggerResource swaggerResource = new SwaggerResource();
        swaggerResource.setName(name);
        swaggerResource.setLocation(location);
        swaggerResource.setSwaggerVersion("2.0");
        return swaggerResource;

    }


}

关键类： swagger资源访问Api

@RestController
@RequestMapping("/swagger-resources")
public class SwaggerHandler {

    @Autowired(required = false)
    private SecurityConfiguration securityConfiguration;

    @Autowired(required = false)
    private UiConfiguration uiConfiguration;

    private final SwaggerResourcesProvider swaggerResources;

    @Autowired
    public SwaggerHandler(SwaggerResourcesProvider swaggerResources) {
        this.swaggerResources = swaggerResources;
    }

    @GetMapping("/configuration/security")
    public Mono<ResponseEntity<SecurityConfiguration>> securityConfiguration() {
        return Mono.just(new ResponseEntity<>(
            Optional.ofNullable(securityConfiguration).orElse(SecurityConfigurationBuilder.builder().build()), HttpStatus.OK));

    }

    @GetMapping("/configuration/ui")
    public Mono<ResponseEntity<UiConfiguration>> uiConfiguration() {
        return Mono.just(new ResponseEntity<>(
            Optional.ofNullable(uiConfiguration).orElse(UiConfigurationBuilder.builder().build()), HttpStatus.OK));
    }

    @GetMapping("")
    public Mono<ResponseEntity> swaggerResources() {
        return Mono.just((new ResponseEntity<>(swaggerResources.get(), HttpStatus.OK)));
    }
}

2. 接口版本化

先分享作者连接： https://blog.mariojd.cn/how-to-design-spring-boot-api-version-number-elegantly.html

效果图：

image.png

image.png

思路：通过RequestMappingHandlerMapping在匹配路径的时候做版本号匹配

关键类: 映射RequestCondition

public class CustomRequestMappingHandlerMapping extends RequestMappingHandlerMapping {

    @Override
    protected RequestCondition<?> getCustomTypeCondition(Class<?> handlerType) {
        // 扫描类上的 @ApiVersion
        ApiVersion apiVersion = AnnotationUtils.findAnnotation(handlerType, ApiVersion.class);
        return createRequestCondition(apiVersion);
    }

    @Override
    protected RequestCondition<?> getCustomMethodCondition(Method method) {
        // 扫描方法上的 @ApiVersion
        ApiVersion apiVersion = AnnotationUtils.findAnnotation(method, ApiVersion.class);
        return createRequestCondition(apiVersion);
    }

    private RequestCondition<ApiVersionCondition> createRequestCondition(ApiVersion apiVersion) {
        if (Objects.isNull(apiVersion)) {
            return null;
        }
        int value = apiVersion.value();
        Assert.isTrue(value >= 1, "Api Version Must be greater than or equal to 1");
        return new ApiVersionCondition(value);
    }

}

关键类: 路径匹配的逻辑

public class ApiVersionCondition implements RequestCondition<ApiVersionCondition> {

    /**
     * 接口路径中的版本号前缀，如: api/v[1-n]/test
     */
    private final static Pattern VERSION_PREFIX_PATTERN = Pattern.compile("/v(\\d+)/");

    private int apiVersion;

    ApiVersionCondition(int apiVersion) {
        this.apiVersion = apiVersion;
    }

    @Override
    public ApiVersionCondition combine(ApiVersionCondition other) {
        // 最近优先原则，方法定义的 @ApiVersion > 类定义的 @ApiVersion
        return new ApiVersionCondition(other.getApiVersion());
    }

    /**
     * 检查当前请求匹配条件和指定请求request是否匹配，如果不匹配返回null，
     * 如果匹配，生成一个新的请求匹配条件，该新的请求匹配条件是当前请求匹配条件
     * 针对指定请求request的剪裁。
     * 举个例子来讲，如果当前请求匹配条件是一个路径匹配条件，包含多个路径匹配模板，
     * 并且其中有些模板和指定请求request匹配，那么返回的新建的请求匹配条件将仅仅
     * 包含和指定请求request匹配的那些路径模板。
     * @param request
     * @return
     */
    @Override
    public ApiVersionCondition getMatchingCondition(HttpServletRequest request) {
        Matcher m = VERSION_PREFIX_PATTERN.matcher(request.getRequestURI());
        if (m.find()) {
            // 获得符合匹配条件的ApiVersionCondition
            int version = Integer.valueOf(m.group(1));
            if (version >= getApiVersion()) {
                return this;
            }
        }
        return null;
    }

    /**
     * 针对指定的请求对象request比较两个请求匹配条件。
     * 该方法假定被比较的两个请求匹配条件都是针对该请求对象request调用了
     * #getMatchingCondition方法得到的，这样才能确保对它们的比较
     * 是针对同一个请求对象request，这样的比较才有意义(最终用来确定谁是
     * 更匹配的条件)。
     *
     * @param other
     * @param request
     * @return
     */
    @Override
    public int compareTo(ApiVersionCondition other, HttpServletRequest request) {
        // 当出现多个符合匹配条件的ApiVersionCondition，优先匹配版本号较大的
        return other.getApiVersion() - getApiVersion();
    }

    public int getApiVersion() {
        return apiVersion;
    }
}

demo项目导入

PS ：本项目使用了JDK11，主要导入的时候要先安装JDK11
参考： https://www.jianshu.com/p/cd0275a2f5fb

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